import { db } from '../db';
import { decrypt } from '../crypto';

// ─── Types ───────────────────────────────────────────────────

interface GraphConfig {
  tenantId:          string;
  clientId:          string;
  clientSecret:      string;
  sharepointSiteId:  string;
  sharepointItemId:  string;
  sharepointSheet:   string;
}

export interface SharepointRowData {
  category:    string;
  companyName: string;
  comment:     string;
  guests:      Array<{ name: string; company?: string | null }>;
  date:        string;   // format JJ/MM/AAAA
  amount:      number;
  userName:    string;   // 'Greg' ou 'Gaël'
}

// ─── Helpers ─────────────────────────────────────────────────

async function getGraphConfig(): Promise<GraphConfig> {
  const result = await db.query(
    `SELECT key, value FROM app_settings
     WHERE key IN (
       'graph_tenant_id', 'graph_client_id', 'graph_client_secret_enc',
       'sharepoint_site_id', 'sharepoint_item_id', 'sharepoint_sheet_name'
     )`
  );
  const cfg: Record<string, string> = {};
  for (const row of result.rows) cfg[row.key] = row.value;

  if (!cfg.graph_tenant_id || !cfg.graph_client_id || !cfg.graph_client_secret_enc) {
    throw new Error('Microsoft Graph non configuré (tenant_id, client_id ou client_secret manquant)');
  }
  if (!cfg.sharepoint_site_id || !cfg.sharepoint_item_id) {
    throw new Error('Fichier Excel SharePoint non configuré (site_id ou item_id manquant dans Paramètres → Microsoft 365)');
  }

  return {
    tenantId:         cfg.graph_tenant_id,
    clientId:         cfg.graph_client_id,
    clientSecret:     decrypt(cfg.graph_client_secret_enc),
    sharepointSiteId: cfg.sharepoint_site_id,
    sharepointItemId: cfg.sharepoint_item_id,
    sharepointSheet:  cfg.sharepoint_sheet_name ?? 'Feuil1',
  };
}

async function getAccessToken(cfg: GraphConfig): Promise<string> {
  const response = await fetch(
    `https://login.microsoftonline.com/${cfg.tenantId}/oauth2/v2.0/token`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
      body: new URLSearchParams({
        grant_type:    'client_credentials',
        client_id:     cfg.clientId,
        client_secret: cfg.clientSecret,
        scope:         'https://graph.microsoft.com/.default',
      }),
    }
  );

  if (!response.ok) {
    const body = await response.text();
    throw new Error(`Obtention token Graph échouée (${response.status}) : ${body}`);
  }

  const data = (await response.json()) as { access_token: string };
  return data.access_token;
}

// ─── Test de connexion (sans écriture) ───────────────────────

/**
 * Vérifie que le token Graph s'obtient et que la feuille Excel est accessible.
 * Utilisé par POST /api/settings/sharepoint/test.
 */
export async function testSharepointConnection(): Promise<void> {
  const cfg   = await getGraphConfig();
  const token = await getAccessToken(cfg);

  const baseUrl = `https://graph.microsoft.com/v1.0/sites/${cfg.sharepointSiteId}/drive/items/${cfg.sharepointItemId}/workbook/worksheets/${encodeURIComponent(cfg.sharepointSheet)}`;
  const resp = await fetch(`${baseUrl}/usedRange?$select=rowCount`, {
    headers: { Authorization: `Bearer ${token}` },
  });

  if (!resp.ok) {
    const body = await resp.text();
    throw new Error(`Impossible d'accéder à la feuille "${cfg.sharepointSheet}" (${resp.status}) : ${body.slice(0, 200)}`);
  }
}

// ─── Fonction principale ──────────────────────────────────────

/**
 * Ajoute une ligne dans le fichier Excel SharePoint commun selon le mapping :
 *   A : Catégorie
 *   B : Société facturée
 *   C : Commentaire + invités
 *   D : Date (JJ/MM/AAAA)
 *   E : Montant si Greg
 *   F : Montant si Gaël
 */
export async function addRowToExcel(row: SharepointRowData): Promise<void> {
  const cfg   = await getGraphConfig();
  const token = await getAccessToken(cfg);

  // Construction de la cellule C (commentaire + invités)
  let cellComment = row.comment || '';
  if (row.guests.length > 0) {
    const guestStr = row.guests
      .map((g) => (g.company ? `${g.name} — ${g.company}` : g.name))
      .join(' ; ');
    cellComment = cellComment
      ? `${cellComment}. Invités : ${guestStr}`
      : `Invités : ${guestStr}`;
  }

  // Colonnes E/F selon l'utilisateur
  const nameLower = row.userName.toLowerCase().normalize('NFD').replace(/[̀-ͯ]/g, '');
  const isGreg = nameLower === 'greg';
  const isGael = nameLower === 'gael';

  const values = [[
    row.category,                 // A
    row.companyName,              // B
    cellComment,                  // C
    row.date,                     // D
    isGreg ? row.amount : null,   // E — Greg
    isGael ? row.amount : null,   // F — Gaël
  ]];

  // ── Trouver la première ligne vide ───────────────────────────
  const baseUrl = `https://graph.microsoft.com/v1.0/sites/${cfg.sharepointSiteId}/drive/items/${cfg.sharepointItemId}/workbook/worksheets/${encodeURIComponent(cfg.sharepointSheet)}`;

  const rangeResp = await fetch(`${baseUrl}/usedRange`, {
    headers: { Authorization: `Bearer ${token}` },
  });

  if (!rangeResp.ok) {
    const body = await rangeResp.text();
    throw new Error(`Graph usedRange échoué (${rangeResp.status}) : ${body}`);
  }

  const rangeData = (await rangeResp.json()) as { rowCount: number };
  const nextRow = rangeData.rowCount + 1;

  // ── Écriture de la nouvelle ligne ────────────────────────────
  const writeResp = await fetch(
    `${baseUrl}/range(address='A${nextRow}:F${nextRow}')`,
    {
      method: 'PATCH',
      headers: {
        Authorization:  `Bearer ${token}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({ values }),
    }
  );

  if (!writeResp.ok) {
    const body = await writeResp.text();
    throw new Error(`Graph écriture ligne échouée (${writeResp.status}) : ${body}`);
  }
}